This invention relates to the method of purifying pollutant gases and the apparatus thereof for the purification of such harmful gases as SO.sub.2, H.sub.2 SO.sub.4, HCl and NH.sub.4 Cl which are inevitably generated for the most part in such places as plating plants, welding sites, chemical plants and pharmaceutical plants.
Also in the past, gas nozzle tubes were installed in the lower part of a large tank, while plural wire nettings were placed in its upper part, in order to purify pollutant gases. On the wire nettings were deposited small-sized granular bodies in a fixed thickness, with water nozzle tubes installed over the beds, so that the surfaces of granular bodies might be wetted by water. The gas from the gas nozzle tube rises and emerges through the granular bodies deposited in multipler. It is a packed tower type purifying apparatus designed to allow only the purified gas to rise by bringing it into contact with the spurted water wetting the surfaces for reaction. However, the contact is only a short period of time in which the gas moves upward by the spurting pressure and buoyancy at a relatively small one-to-one contact volume ratio with water, resulting in a low purifying efficiency and also constituting a decisively defective factor in the practical use. Its structure is complicated and entails a problem of the said facility becoming enormous.
Also, as another type of the apparatus, there is an agitation type purifying apparatus. Gas nozzle tubes are installed in the lower part of the tank which is filled with water while a motor-driven propeller is fitted above them so that the bubbles generated by the gas nozzle tubes are broken up by the propeller and react in contact with water. This way only the purified gas rises and then it is vented. However, since there is a limit to improving the gyration power of water even though the rotation speed of the propeller is increased, it is difficult to increase their rising velocity of the bubbles. As a result, the contact time with water becomes short and the harmful gas fails to sufficiently react with water. In this connection, it poses the problem of a lowered purifying efficiency, necessitating the use of a large propeller of the almost the same diameter as the tank. Its driving causes vibration and noise while increasing electric power charges. Moreover, the bubbles in the central part of the propeller and outside the both ends do not receive any particular gyration power and rises upward to cause the further lowering of the purifying efficiency.